Coherent scatter in diagnostic radiology

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Med. Phys.; (United States)

DOI:https://doi.org/10.1118/1.595443· OSTI ID:6515957

Johns, P C; Yaffe, M J

Coherent scatter is often ignored in diagnostic radiology because its cross section is relatively small, and because it is assumed to be indistinguishable from primary radiation. Single-scatter calculations, however, show that coherently scattered photons diverge sufficiently from the primary ray to degrade image contrast, and that they account for a significant fraction of the total scattered energy fluence at the image receptor. Grids and large air gaps are less effective in reducing coherent single scatter than incoherent and multiple scatter. For radiography of the abdomen, coherent first scatter comprises 10% of total scatter and 26% of the primary fluence before a grid, and on the order of 22% and 7.5%, respectively, behind a grid. Coherent first scatter comprises a higher fraction of the total amount of scatter for lower energy examinations such as mammography. Key words: diagnostic radiology, scattered radiation, coherent scatter, x-ray diffraction

• Research Organization: Department of Medical Biophysics, University of Toronto, 500 Sherbourne Street, Toronto, Ontario, M4X 1K9, Canada
• OSTI ID: 6515957
• Journal Information: Med. Phys.; (United States), Journal Name: Med. Phys.; (United States) Vol. 10:1; ISSN MPHYA
• Country of Publication: United States
• Language: English

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AIR
BIOMEDICAL RADIOGRAPHY
COHERENT SCATTERING
CROSS SECTIONS
DIAGNOSTIC TECHNIQUES
DIFFRACTION
DOSIMETRY
ELECTROMAGNETIC RADIATION
ESTERS
FLUIDS
GASES
HYDROGEN COMPOUNDS
IMAGES
IONIZING RADIATIONS
LUCITE
MATERIALS
MEDICINE
MOCKUP
NUCLEAR MEDICINE
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHANTOMS
PLASTICS
PLEXIGLAS
POLYACRYLATES
POLYMERS
POLYVINYLS
RADIATION DOSE DISTRIBUTIONS
RADIATIONS
RADIOLOGY
SCATTERING
SIGNAL-TO-NOISE RATIO
SPATIAL DOSE DISTRIBUTIONS
STRUCTURAL MODELS
SYNTHETIC MATERIALS
WATER
X RADIATION
X-RAY DIFFRACTION
X-RAY DOSIMETRY